Cheat Sheet No. 2: A Perfect Week of Exercise
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There’s a research-backed way to strengthen your heart, and while you’re at it, your muscles, bones and mind. It doesn’t require hours of exercise, newfangled equipment, or a trainer — just a smart combination of cardio intervals, weights, and yep, a little yoga. How it breaks down:

Cardio: You want at least two sessions of steady-pace aerobic cardio at 65 to 75 percent of your maximum heart rate for 30 to 45 minutes. Also include two 20-minute bouts of high-intensity interval training. (Here's a solid go-to: Choose any form of cardio you want, and warm up for five minutes. Alternate going all-out for one minute, and recovering for one minute, for 10 minutes. Cool down for five minutes.)

Strength: Log two 30-minute workouts by any method you choose: body-weight resistance (push-ups, pull-ups, etc.) or dumbbells – or try a one-two punch by mixing strength and cardio in a routine with kettlebells, pool workouts with weights, or fast-paced circuit training.

Flexibility: Stretch every day for 10 minutes. An alternative: vinyasa-style yoga, which combines flexibility and strength work with a stress-reducing mindfulness component that can help protect the heart vessels against roller-coaster stress hormones. Need more convincing? In one Yale study, people who took a six-week yoga-and-meditation program saw the function of their blood vessels improve by 17 percent.